Integrated circuit memory cards have become popular as a means of conveniently adding memory capacity to personal computers, particularly palm top, lap top, and notebook-sized computers, as well as other devices such as modems, serial ports, cellular phone links, facsimile machines, application read-only memories, etc. To promote compatibility among memory cards, physical, interface and software standards have been adopted by the Personal Computer Memory Card International Association (PCMCIA) in the United States and by the Japan Electronics Industry Development Association (JEIDA). The current PCMCIA Card Standard (Release 2.0, September 1991), which is incorporated herein by reference, provides for two physical sizes, designated Type I and Type II, which are distinguished from each other primarily by specifying card thicknesses of 3.3 mm and 5.0 mm, respectively. The memory cards are provided with a 68-pin socket connector at one end and are typically guided into place by a pair of channel guides which engage the side edges of the card.
Integrated circuit memory cards permit up to about 20 megabytes of storage to be added to the host computer. Recently, it has been proposed that the PCMCIA adopt several additional size standards, designated Type III and Type IV, specifying card thicknesses of 10.5 mm and a greater thickness in the range 12.5-18.0 mm. These larger sizes raise the possibility of substituting a small disk drive, having disks 1.8 inches in diameter, for example, in place of the solid state memory. This would permit a substantially larger memory capacity, e.g., 100 megabytes, to be added to the host computer.
At present, disk drives are generally mounted in small computers by means of screw fasteners and are connected electrically by means of a cable and a connector. Alternatively, the drive may have a built-in connector and may be mounted onto the computer directly with some type of retaining means. A disk drive compatible with PCMCIA specifications could more easily be mounted in a computer, without special technical training or extra hardware, either as a part of the manufacturing process or as a field replacement or upgrade. Such a drive could also be used as a removable storage device.